The present invention relates to the monitoring of cervical dilatation during labor.
Traditionally cervical dilatation is estimated by the physician through a vaginal examination. Accordingly, this measurement cannot be made on a continuous basis and only provides a rough estimate of actual cervical dilatation.
While various devices have been devised to assist the physician in measuring cervical dilatation via a vaginal examination, they do not provide the capability of measuring cervical dilatation on a continuous basis over time.
Still other devices have attempted to provide a continuous dilatation monitoring capability. Such devices are constructed as calipers designed to attach to diametrically opposed surfaces of the external os of the cervix. As the cervix dilates, the degree of separation of the caliper arms is monitored to measure the dilatation. The ends of the caliper arms must however, be securely fixed to the external os, so that such devices typically provide needles or barbs which cut into the cervical tissues to prevent the caliper arms from being loosened from the cervix during labor. Obviously, such devices pose a substantial risk of injury to the cervical tissues. They are also relatively complex and difficult to use.